Pressure-gage.



54G. BAILEY. PRESSURE GAGE. APPLIGATIOH FILED A UGIU, 1914.

,mmemc; 29, 1914.

'ceiving hell 2 which EBVIN G. BAILEY, 0F NEWTON. MBQSACHUSETTS.

rnnssnnn-enen Specification of Letters Patent.

Patented Dec, 29, 1914.

indication filed August 11, 1914. Serial No. 856.237.

To aZZ whom it may concern":

l3e it known that l, Envn: G. Bunny, :1 citizen of the Un ted States, residing in Newton, in the" county of Middlesex and State of Massachusetts, have invented :in

Improvement in Pressure-Gages, of which the following description, in connection with the accompanying drawings, is a specilicntion, like letters on the drawings representing like per-ls.

The present invention relates to u pressure gage and embodied in an instrument for indicating and recording vuriutions in pressures, the inslrument being particularly adapted for use in connection with fluid flow meters.

The purpose oi the invention is to simplii'y to the greatest exienl; possible the coin struction and arrangement of such an insirument and at the some time to eliminate friction so for us is possible so that the in strumeni; is ver sensitive and therefore highly eilicicnt.

A further feature of the invention consists in providing the inszruuienl with means whereby an excessive pressure (lilierencc due, for example to the breaking of a pipe or to any other cause will be COlllltEl'ZU'tfitd in such a way to prevent damage.

Figure 1 is 5 front elevation, pzirtl in section, showing an instrumentembodying the invention: and Fig. 2 is a transverse section through the middle of Fig. l.

The instrument en'ibodying the invention consists of 2 casing or chamber 1 which is adapted to receive ihe full pressure of the steamer of any other iluid which is to be metered. Within the chamber a pressure resubznerged in a liquilh preferably mercury, contained-in a chamber 3. the interior of said bell being adapted to receive pressure through on inlet pipe -1- extending through the mercury in the rose"- voir to the interior of the bell; while the terior of the bell receives pressure on the outside which is admitted to the chamber 1 through a pipe The hell 2 is conne ted \With an oscillatable beam or lever 6 which has a pivotal hearing consistingof u spindle extending through suitable pressure tight bearings 7 to theeutside of the casingihe said spindle having connected therewith :m indicating pointer a which is shown adapted to be provided with a pen which marks a rotating chart 9 for recording purposes. The walls of the hell 2 are of material thickness, as indicated at 10, so that the change in the buoyancy of the hell as it moves into or out of the mercury eventually will balance the change in force due to pressure acting on the bell. The position of the imliczitor which is moved in response to the movement oi" the bell. is therefore, a measure ofthe pressure 'lillerence necessary to bring about the state of equilibrium aforesaid. in order to obviate the necessity of the use of guides or other devi es which 'are productive oi objectionable friction, the bell is urrungcrl to be held in its vertical position under all coudilions of pressure by menu; of an external weight 11 which is outside of the scaling liquid and is connected with the bell in such a way that its center of gravity is always below the center of buoy- ;mr-v of the bell. thereby causing equilibrium of flotution of the bell at all times. If it is desired to bring, about :1 state of equilibrium when the indicator 8 shows a reading-which vurirs. not directly with the pressure difference. but as some function thereof, such as the functional relation between the velocity heed and rote or flow of fluids, the wall of the v horizontu cross-sectional areu of the said wall at tie surface of the liquid progres sivelv vuricsns the'bcll moves, lberebv modifying the change in buoyancy due to such movement. ll: is obvious, however, that the bell and its walls may be of any known or desired shape according to the reading which is desired, and it is to be understood that no claim is made involving the peculiar shape of this bell. 1

In order to prevent accidents due to-an u'onorrnal excess of either sure, over the bell may be shaped as indicutcd so that the other, which might resuli in blowing outthe liquid which seals the hell, i hsvepro- \ided the instrument with means whereby the extrei'ne movement of he bell in either direction will close one of the pressure pipes, tbere v trapping the excess pressure and Slflmnfigillfi normal operation of the instrument. As a simple expedient for this purpose, I have shown the pressure inlet pipes luncl as in line with each other and in line with the axis of the bell, the said bell being provided al the outside with u valve memberlz and at the inside with :1 valve member 13 which are adopted to cooperate respectively with the ends bf the inlet ducts 5 and 4. As 'the instrument is commonly used, the pressure medium contained mthe casing l is water, which is non-compressible. It being obvious therefore that if either pressure is in excess of theother -und the passage for the other is stopped,'thelexcess pressure will be trapped sothat the' mercu in which the bell is submergedcannot be lown out of the receptacle. Assuming,

however, that .a compressible medium is employedinstead of a liquid, the compression willbe sufficient to overcome the excess pressure in all ordinary cases before the mercury can be displaced so as to cause damage. I have providedthe casingl with a passage 1% controlled by a valve 15 whereby communication canbe established between the ducts through which pressure is de- ,livered to the inside and the outside of the "bell respectively so as to bring about a state of equilibrium between the pressures.

What I claim is:

1. Ina pressure gage, the combination with a pressure receiving bell sealed in a liquid and having Walls of sufiicient thickness to bring about a state of equilibrium due to the buoyant effect of the sealing bell in the liquid; ofan oscillatable beam to'which said bell is connected; and a weight associated with said bell and solocated with relationithereto that the center of gravity of the bell and weight is always below their center of support. I

prising a liquid 3.-'A pressure gage co sealed bell; a pressure receiving casing containing said sealed bell; a pressure duct opening into the space within the said bell and above the sealing liquid, the outer edges of said duct also forming a stop'upon which the said bell rcsts when at its lou'er limit of motion; another pressure duct opening into the space above the bell, the lower edges of said duct also forming a stop for said bell when at its uppermost limit of motion; and suitable surfaces on the outer and inner parts of said bell to seal Wl'llClICVQI opening is engaged when there 1s an extreme movement of said hell.

4;. ln a pressure gage, the combination with a pressure YQCBlYlIlg bell scaled in a liquid and having Walls of sullicient thickness to bring about a state of equilibrium due to the buoyant client of the sealing liquid on said bell; of an. oscillatable beam to which said bell is connected; a weight connected with said bell and outside of the liquid in which said bell is scaled, the center oi gravity of said weight being below the center of gravity of said bell; a casing containing said sealed bell; pressurepipes lead ,ing respectively into the said casing outside fifth? bell and through the sealing liquid -to the inside of the bell; and means for closing either one of said pipes in response toan abnormal-movement of the bell.

In testimony whereof, I have-signed my name to this specification in the presence of two subscribing witnesses.

ERVIN G. BAILEY.

Witnesses:

JAs. J. Mercury, M. L. MALONEY. 

